Feedback for October 2001

Quick question. Back in the 1960's there was one or several experiments that resulted in the start of life from non-living matter. If one of you can remember the study or published article, can I get the name?

"1. Explain how irreversibly complex systems evolve.

2. Explain how legs can turn to wings without a time where the apendages are good as neither.

3. Explain how evolved species find compatible mates.

4. Explain how sea dwelling creatures evolve land dwelling lungs, and back again.

5. Explain how species survived before they'd evolved the biological processes necessary for survival, like spiders and their webs.

6. Explain how we survived while our stomachs developed, and we former sea dwelling organisms evolved to consume land food.

7. Explain why hoaxes that were uncovered by scientists decades ago still show up in text books as fact.(They are referring to the Piltdown Man here, they claimed that this was still being taught in schools...)

Any help would be very appreciated. Thx, Zach

When are we likely to be able to read the feedback post June? One of my chief delights was to read the posts and the answers to them, but since early July, there has been nothing new. Are you just too busy?

Sincerely

Larry A. Cornell

Please reply.

I hate to point out a flaw in your usually explemplary website, but a section in the "Are Mutations Harmful?" FAQ is 'bugging' me (ouch, sorry about the pun):

Regarding peppered moths, Richard Harter writes,

"Kettlewell's explanation (which makes for an appealing story) has not stood the test of time. Peppered moths seldom rest on exposed areas of the trunks of trees. Moreover the distribution of dark moths might not be well correlated with tree color except in the areas which Kettlewell studied. Some more recent studies indicate that peppered moth melanism is very well correlated with the amount of SO2 (sulfur dioxide) in the air. [5]"

...and he cites an article by none other than Discovery Institute Fellow Jonathan Wells, author of the recently infamous book Icons of Evolution".

Footnote 5 continues:

[5] Johnathan Wells has written an excellent summary article on the peppered moth which should not be taken as being definitive. The topic is the subject of considerable controversy. For dissenting commentary see: Peppered Moths - round 2 (part 1 of 2) and Peppered Moths - round 2 (part 2 of 2).

...citing Wells' article at trueorigins, talkorigins' arch-nemesis!

(It's spelled JONATHAN, BTW)

Now, it is laudable to cite one's opponents if they do indeed succeed in making a legitimate point. However, my sense of it is that Wells has succeeded only in taking the mistakes of some scientists (namely Jerry Coyne's misguided review of Majerus' Melanism: Evolution in Action in Nature) and then further exaggerating the plight of the moth story via the usual tactics of selective quotation and condemnatory allusion.

Fortunately the footnote cites the alternative view posted (if I recall correctly) by Donald Frack on the Calvin listserv. Based on the helpful discussion there, I read Majerus' book, the review of the book Coyne (upon which Wells built his case), and subsequent commentary by the moth experts on the situation. My points follow:

1) Here is Jerry Coyne (Nature) review:

Not black and white

...and I can confirm Frack's opinion that there is very little relation between Coyne's review of Majerus and the actual chapters of Majerus' book. For example, Coyne says in his review:

"Majerus notes that the most serious problem is that B. betularia probably does not rest on tree trunks exactly two moths have been seen in such a position in more than 40 years of intensive search. The natural resting spots are, in fact, a mystery."

...but, Coyne completely fails to mention that in the very next paragraph of Majerus' book, Majerus cites his own data on the natural resting places of moths -- some 47 moths -- not alot, but far more than two. This alone, in an article in Nature, furgoodnesssakes, is sufficient reason to discount Coyne's review (let alone Wells' further exaggerations of the issue). Of the 47 moths, Majerus found:

6 on exposed trunks 6 on unexposed trunks 20 on trunk/branch joints 15 in branches

...which indicates that, in fact, some 68% of the available natural sample actually does rest on trunk of some sort, contra Coyne and Wells. It is hard to see how Coyne missed this dataset, as Majerus also mentions it in the first lines of his preface (he's been collecting for his whole career -- peppered moths are not easy to find, because, well, they're camoflagued, which is the whole point).

(Frack lists the numbers here: Peppered Moths - round 2 (part 1 of 2) )

Now, sure, it may be that the moths rest in branches as well as trunks, and the relative proportions are somewhat debatable given the limited dataset (although, the much more extensive 'moths found near traps' data of Majerus has at least comparable proportions, which would suggest that the near-traps data is at least somewhat representative as well -- some 136 out of 156 moths were found on trunks of some sort, and 48/156 on exposed trunks in this case, although the attraction of the traps doubtlessly biases this data somewhat). And even if you ignore the data and imagine that moths are found entirely in tree branches, as Wells implies, well, lichens and birds (being known flying creatures) are also often found in tree branches, so it seems that the bird predation hypothesis at least remains quite reasonable.

I suspect that either Coyne was just having an off-day when he wrote the review, or he was influenced by Sargent et al.'s review hypothesizing other causes (but apparently without any supporting evidence, unlike the selective-predation-by-birds hypothesis) and by his 'higher goal', namely communicating his concluding point: "We must stop pretending that we understand the course of natural selection as soon as we have calculated the relative fitness of different traits."

...which may be true in other cases, but almost certainly not in the case of peppered moths. I've read several recent scientific articles by actual professional entomologists, and none of them seem to think that the natural-selection-by-differential-bird-predation hypothesis is anything like the "peppered myth" that Wells asserts.

Numerous additional points could be made about Wells' scholarship (see: Icons of Anti-Evolution and the thread on the ARN design forum which references Frack's critiques of Wells, here: Topic: Wells not incompetent on peppered moths ). The whole thing is really deserving of a very long FAQ, given the multitude of creationist and ID webpages trumpeting the death of the peppered moth. [After this page was originally posted, Nic wrote the first of this Archive's Icons of Evolution FAQs. See it for more details.] Frack says:

The bottom line is this: not only is the peppered moth scenario not dead, it isn't even sick; it is still considered to be an example of "evolution in action" even though the scenario is not as simple as it is frequently portrayed to be.

And Majerus himself (who replied to Frack) confirms:

Evidence of selective predation in the peppered moth is not lacking. It is just not provided in the quick text book descriptions of the peppered moth. How can it be. I have read some 500 papers on melanism in the Lepidoptera. In total, these papers probably amount to about 8000 pages, ad the story is condensed into a few paragraphs in most textbooks for schools. Even in my own book, I could only give a review of the case covering about 60 pages including illustrations.

The older hypothesis that melanism was induced by pollutants was discredited because eslop Hassison's experiments lacked appropriate controls, and his results could not be replicated, despite several attempts. Furthermore, the levels of mutagenesis that he recorded are several times higher than those produced by doses of radiation that induce complete sterility in fruit flies (see E.B. Ford (1964) Ecological Genetics for full critical review).

Finally, I agree with Dr Wells that photographs of two peppered moths staged on backgrounds for effect should say they have been done purely for illustrative purposes. I have many times, in undergraduate lectures, pointed out that photographs of the type that appear in so many text books are faked. However, I would point out that none of the photographs of live peppered moths taken by myself, which appear in the book were staged. All show peppered moths where they were found in the wild.

End-note: It is difficult to have an informed discussion of a complicated ecological system with those who have little or no experience of the system. My advice to anyone who wishes to obtain a fully objective view of this case is to a) read the primary papers that I based my review upon, and any other relevant papers, and b) gain some experience of this moth and its habits in the wild. Of all the people I know, including both amateur and professional entomologists who have experience of this moth, I know of none who doubts that differential bird predation is of primary importance in the spread and decline of melanism in the peppered moth.

I hope that this is some use to you, Donald, and that it encourages more people to look at the case of the peppered moth with an open mind. If it can help interest a few more people in moths and butterflies, that is all to the good.

Best wishes, and Happy Easter.

Mike Majerus

Anyhow, hopefully you'll print this letter, or get Donald Frack's permission to repost his discussion on your website, or get a FAQ up on this topic. At the very least, perhaps you can reference several recent publications from Actual Moth Researchers which defend the essential elements of the peppered moth 'story' -- namely, that differential bird predation (and migration) are the primary factors accounting for the rise and fall of the melanic form of the peppered moth over the past 150 years. Here those are:

Bruce Grant's webpage

Grant, Bruce S. 1999. Fine tuning the peppered moth paradigm. Evolution 53: 980-984.

(a brief treatment of Grant's work: Back and Forth, and Back Again: Biologist makes an unprecedented discovery about one of the most noted examples of evolution in nature.)

And a specific recent review defending the conclusion that differential bird predation is the selective force that is acting on moths:

Cook, L. M. 2000. Changing views on peppered moths. Biological Journal of the Linnean Society, 69: 431-441.

This last article is not about how moth researchers are ditching the conventional view of peppered moths; it is *about* the odd fact that 'conventional wisdom' on the peppered moths has been changing in the public and even with scientists like Coyne, despite the fact that the actual researchers like Grant, Majerus, and Cook, do not think that any radical change is necessary.

The abstract:

The rapid rise in frequency of melanic morphs in several moth species, especially the peppered moth Biston betularia, in industrial regions during the 19th century, and the subsequent rapid decline, indicate the action of strong selection. There has recently been a tendency to criticise and question all aspects of research on industrial melanism, including the experiments which suggest that selective predation plays an important part in the changes. These experiments are reexamined, together with evidence for changes in appearance of tree surfaces and for relation of initial melanic frequency to subsequent rate of decline. It is suggested that intense pollution may have been required to drive the carbonaria morph to a high frequency, with frequency patterns over a mosaic environment smoothed by migration. Improvements in these extreme locations then triggered the decline, with little indication of the environmental changes in areas of moderate pollution. Reasons for criticism of past work are discussed. Industrial melanism continues to provide an exceptional opportunity to analyse a pattern of selection and change in gene frequency.

...and some quotes:

Work by H. B. D. Kettlewell suggested that selective predation was the main determining factor in B. betularia, and probably in a wide range of other examples as well. His evidence consisted of surveys which put the correlation between melanic frequencies and urbanization on a quantitative basis (Kettlewell, 1958, 1965), demonstration that wild birds would eat the moths if they found them (Kettlewell, 1955), and the now famous demonstration that birds discovered most readily the forms least like the daytime backgrounds on which they rested (Kettlewell, 1973; Rudge, 1999). Colour of resting background and heterogeneity due to epiphyte cover, appeared to aVect relative visibility. Selective predation became the accepted explanation for the rise in morph frequency (Majerus, 1998).

Since then, further evidence has been collected. Over the last two decades industrial environments have become cleaner and melanic frequencies lower (Clarke et al., 1990; Mani & Majerus, 1993; Grant et al., 1998; Cook et al., 1999). There has also been some revision of interpretation. It has been shown that experiments designed to detect and measure selective predation were carried out in places where moths were not usually likely to rest if left to their own devices (Mikkola, 1979, 1984; Liebert & Brakefield, 1987; Grant & Howlett, 1988; Majerus, 1998). There is by no means a one-to-one relation between reversion of morph frequency and reversion of epiphyte pattern (Bates et al., 1990; Grant et al., 1998). These findings cause us to reexamine the story, but they do not obviously require a radical revision. Estimations of selection appear to show a correspondence between fitness and frequency. The correlation between the condition of the sites used in experimental studies and those actually used by the insects is likely to be high. Further lines of experimentation are suggested, but no previously held view has been overturned.

The general tone of commentary on Biston studies has, however, altered. From being treated as a vivid demonstration of natural selection (Luria, Gould & Singer, 1981, provide an excellent example) and good field experimentation (Hagen, 1999), the work concerned has come to be viewed with suspicion (Sermonti & Catastini, 1984; Cherfas, 1987). In a recent review by Sargent et al. (1998) almost every reference to past work is predicated by expressions of doubt, reworking ground covered by Lambert et al. (1986). When discussing predation experiments they conclude ". . . there seems to be no clear and consistent relationship between the relative survivorship of diVerent morphs . . . and the frequencies at which the morphs naturally occur in diVerent environments". Coyne (1998) adopts a similar tone, saying that the flaws in the work are too numerous to list. This has led to some alarming reporting, such as Matthews (1999) in the Daily Telegraph newspaper in Britain, who refers to a "series of scientific blunders" and states that the experiments are "now thought to be worthless". This article in turn was linked in its electronic web version to the Creation Science home page. Recent commentaries are quoted on more than one anti-evolution web site. A balanced account, which shows the strength of the data in the face of recent criticism, has been provided by Grant (1999). I propose here to illustrate the predation results, which Sargent et al. did not do when they criticized them, and to consider why a radical change in view should have occurred.

[...]

CONCLUSION

In industrial melanism of Biston betularia, both the original increase and recent decline in frequency of melanics are striking examples of natural genetic change closely related to change in the environment. They must have a selective basis. The experiments demonstrate selective removal. There is a general correspondence of morph frequency and appearance of backgrounds likely to be adult resting sites. None of this is in doubt. The evidence is, however, limited in two ways. First, non-visual components of selection have not been investigated directly in this species. Analysis of segregating progenies suggests pre-adult survival diVerences (Creed et al., 1980) with carbonaria homozygotes having an advantage over other morphs. Non-visual selection is certainly indicated in studies of other melanic moths (Bishop & Cook, 1980), but we have little more idea than Leigh (1911) how it may operate. [Next is Cook's summary of "why a radical change in view should have occurred"] Secondly, the experimental and observational evidence cannot on its own carry the burden of a particular view of evolution, such as found in Oxford ecological genetics. Smocovitis (1996) describes how the view of the Synthesis with which it was associated came to seem ‘constricted’ to many students of evolution, and to generate a reaction in favour of more complex models; the last three decades have been a period of lively debate and controversy. Distrust of the evidence of industrial melanism may sometimes arise from a wish to question how the example relates to more complex levels of evolutionary theory. Criticism on these grounds is misplaced, and can attract the attention of advocates of creationism who see an evolutionary field in apparent disarray. The Biston story continues to provide an exceptional opportunity to analyse a pattern of selection. It should be pursued, along with study of other species with related but different responses to environmental change.

...which just about does Wells in, IMO. The essential points of the classical peppered moth story remain firm. Keep it in the textbooks.

Thanks, Nic Tamzek

PS: While I'm at it, the FAQ "Bombardier Beetles and the Argument of Design" has the line "Creationists have argued for an appearance of design in everything from bacteria cilia to butterfly metamorphosis." I suspect that "bacterial flagella" was meant.

OK, I'm done. Those are literally the only two corrections I could find, so now you're clean :-) . Seriously, keep up the good work.

Thank you.

Chris: PLEASE read Stephen Jay Gould's "The Tallest Tale", found in his collection Leonardo's Mountain of Clams and the Diet of Worms, and printed in Gould's column in Natural History Magazine (in 1996, I think).

Also check out this article: "The Imaginary Lamarck: A Look at Bogus "History" in Schoolbooks" by Michael T. Ghiselin.

And then, please, correct what you have written.

I had read Gould's article when it first came out, then forgot about it until I repeated the giraffe story to my students (I teach a 100-level botany course at a state college). I was being observed by another professor that day, who was aware of Gould's historical research, and he reminded me of what I should have remembered. Guess I shouldn't be too embarrassed, since, as Gould points out, every single high school and college text repeats this same old misleading tale. It would be good to change that, though, as well as to ferret out any other nonsense from our science texts.

This doesn't have much directly to do with the "Evolution/Creation Controversy", except perhaps for giving the creationists some ammunition, but it should remind us that even the best sources are not infallible....

-Al Stoops